The role of sciatic nerve block to complement femoral nerve block in total knee arthroplasty: a meta-analysis of randomized controlled trials.

introductionFemoral nerve block (FNB) appears to have higher postoperative analgesic benefits compared with the patient-controlled analgesia (PCA) in total knee arthroplasty (TKA). However, the role of sciatic nerve block (SNB) as a complement to FNB remains controversial. We performed a meta-analysis assessing the benefits of the SNB as a complement to FNB, as well as comparing the efficacy of single-injection versus continuous SNB in TKA.

methodsOur group conducted a systematic literature search in PubMed, EMBASE and Google Scholar. We retrieved randomized trials comparing either SNB versus placebo or continuous versus single-injection SNB. The intervention group was the use of SNB as a complement to FNB, while the control group was FNB alone. Pain score at rest and movement (at 4, 12, 24, 48 and 72 h), patient-controlled intravenous opioid consumption, length of hospital stay, and incidence of nausea were extracted from each study. Random-effects model was used for meta-analysis and standardized mean difference (SMD) was used as the effect size.

resultsTen articles comprising 514 patients were included to compare the effects of SNB combined with FNB versus FNB alone. Interventional group was found to significantly reduce pain score at for 4 h (SMD = - 0.94, 95% CI - 1.42 to - 0.47, P < 0.001, I

conclusionsThis meta-analysis provides evidence-based supports to the benefits of SNB as a complement to FNB in TKA. The combination sciatic-femoral nerve block appears to be the optimal choice for patients in high risk of postoperative opioids consumption or acute pain after TKA.